So-called "balloon" shades are currently enjoying considerable popularity as window treatments, particularly for home decoration use. Structurally, such shades consist of a panel of supple fabric, to the back of which a number of rings or similar elements are secured in a pattern of columns and rows. The rings serve to guide several drawstrings from points of attachment near the bottom to points near the top, and then across the shade to a common location adjacent one side, for simultaneous operation. The shades are designed to be hung from an overhead rod, and will usually have a stiffening strip inserted along the bottom edge to help maintain proper conformation.
Heretofore, it has been the practice to affix the uppermost guide elements directly to the rigid supporting rod, to ensure that the attachment will be strong enough to avoid disengagement. Drawstring directional changes are effected by those elements, and they are consequently subjected to rather substantial levels of force. In addition, attachment to the rod prevents sliding and gathering of the fabric at the top of the shade, which would otherwise also tend to occur in response to movement of the drawstrings.
A primary disadvantage of the conventional construction resides in the fact that it makes it impossible to string the shade prior to assembly with the supporting rod; prestringing is of course highly desirable from the standpoint of customer convenience and, accordingly, for consumer appeal. Furnishing the shade in prestrung condition, on the rod, would on the other hand hamper standardization of sizes, since the length of the rod must conform to the width of the window on which the shade is to be installed. It would, moreover, virtually preclude mail-order sales, since shipment in a flat (i.e., folded) condition would therefore be rendered impossible.
A considerable variety of shade and curtain constructions is disclosed in the prior art, as evidenced by the following U.S. Pat. Nos. 1,956,116; 2,528,652; 2,620,027; 2,910,120; 3,160,202; 3,528,477; 3,593,772; 3,777,800; 3,913,655; 3,952,788; 3,999,590; 4,069,857; 4,088,170; and 4,397,346. More particularly, in U.S. Pat. Nos. 2,910,120 and 3,160,202, Rosen describes curtains in which drawstrings are threaded through eyelets secured in the area of a hem, and conventional rods are apparently used for supporting the curtains; the cords extend vertically through "tubes" defined by tapes attached to the material of the curtain. In Koch, U.S. Pat. No. 3,999,590, carriers affixed to the curtain are also attached to an overhead rail; the carriers have ring portions which cooperate with loops for guiding the operating cords.
Attempts have been made to design shades of this sort to allow prestringing off the supporting rod, such as by providing fixtures to be subsequently attached to the rod during installation, through which fixtures the cords are threaded by the manufacturer. This has been found, however, to be at best an awkward solution, and to necessitate the use of complex and cumbersome packaging. Thus, despite prior efforts, a need remains for a balloon-type shade which can be furnished in prestrung condition, apart from any supporting rod, and which can be conveniently folded and packaged for shipment.
Accordingly, it is an object of the present invention to provide a novel balloon-type shade which can be furnished in standardized widths, in prestrung condition, and independently of any supporting rod.
It is also an object of the invention to provide such a shade which will operate in a smooth and reliable manner, without undue shifting on the supporting rod.
Another object is to provide a novel balloon shade having the foregoing features and advantages, which is attractive, durable, relatively uncomplicated and inexpensive to manufacture, and easy to install.